Brown the Butter:
Melt butter in a heavy-bottom saucepan over medium heat. Stir until golden brown bits form and it smells nutty. Remove from heat and pour into a bowl. Cool for 30 minutes until room temperature but still liquid.

Blot the Pumpkin:
Spread pumpkin puree on layered paper towels in a shallow bowl. Let the paper towels absorb excess moisture. Squeeze lightly, then measure ½ cup (125g) of dried pumpkin.

Mix Dry Ingredients:
In a separate bowl, whisk flour, pumpkin (or chai) spice, baking soda, and salt. Set aside.

Mix Wet Ingredients:
In a large bowl, stir together the cooled brown butter, brown sugar, and maple syrup until combined. Add egg yolk, blotted pumpkin, vanilla, and optional maple extract; mix until smooth.

Combine:
Stir the dry ingredients into the wet ingredients until just combined. Cover the dough with plastic wrap and chill for 8 hours or overnight.

Prep to Bake:
Remove dough from fridge and rest at room temperature for 30 minutes to soften slightly. Preheat oven to 350°F (177°C) and line baking sheets with parchment paper.

Make Spiced Sugar:
Mix sugar and pumpkin (or chai) spice together in a small bowl. Adjust spice balance to taste.

Shape & Coat:
Scoop dough with a 2-inch cookie scoop, roll in spiced sugar, and place 2–3 inches apart on baking sheets.

Bake:
Bake for 12–14 minutes, checking at 9–10 minutes. If cookies are puffier than desired, lift and bang the pan on the oven rack to help flatten, then bake 3–4 more minutes until set and chewy.

Cool & Serve:
Let cookies cool on the baking sheet for 3–5 minutes, then transfer to a wire rack to cool completely.